1. Field of the Invention
The present invention is directed to an anti-skid brake control system and more specifically to such a system having a brake actuator wherein the actuator operating pressure is automatically adjusted to a level proportional to the level of the pressure from the brake booster to enhance the responsiveness of the actuator.
2. Prior Art
In applicant's co-pending application Ser. No. 663,031, filed Mar. 2, 1976 entitled "Anti-Skid Brake Control Device for Vehicles" now U.S. Pat. No. 4,027,924 granted June 7, 1977, the pressure which operates the actuator is adjusted to the pressure from the master cylinder whereas in the present application the pressure which operates the actuator is adjusted to the pressure from the brake booster. Generally, the fluid utilized in the master cylinder is made of vegetable oil while the fluid utilized in the booster or power steering, which is also arranged in the hydraulic pressure circuit, is made of mineral oil. In view of this face, the pistons 29, 30 and 31 of prior application Ser. No. 663,031 were provided with sealing rings as illustrated in FIG. 1 of that application in order to avoid a mixture of the oils between the chamber 32 which contained mineral oil and the passage 68 which contained vegetable oil. As a result the sealing ring is provided with considerable sliding resistance which reduced the responsiveness of the pistons upon sliding movement thereof.